The present invention relates generally to an environmentally safe insecticide and more particularly to novel compositions which are safe for both plant life and vertebrates in general, including human beings, but which are toxic to invertebrate pests such as insects. The composition has the further unexpected benefit of repelling mosquitoes when applied to human skin.
Heretofore, insecticides used for chemically controlling insect infestation fell into five major categories namely, chlorinated hydrocarbons such as LINDANE, METHOXYCHLOR, and the like; organophosphates such as MALATHION, DIBROM, DIAZINON, PHOSPHAMIDON and the like; carbonate compounds such as BAYGON, SEVIN and the like; inorganic compounds such as, arsenic, sulphur, borax, and the like; and botanical compounds such as pyrethrin, strychnine, nicotine, and the like.
The prior chemical insecticides, excluding the botanical compounds, possess several disadvantages. Most of them are highly toxic to fish, wildlife and humans and must be used with caution. Further, the active ingredients are generally not naturally occurring biological constituents and, as such, tend to persist for long lengths of time after their initial application. Consider, for example, the chlorinated hydrocarbons (Petrochemical hydrocarbons are suspect carcinogenic agents) which because of their persistence have been shown to pass through the animal food chain and cause egg shell thinning and egg breakage in many species of birds.
Besides their initial toxic effect, these compounds have sub-acute effects on non-target fauna and flora thereby causing biochemical, behavioral and physiological changes as well as reproductive failure. Furthermore, their adverse effect on the environment in general is widely known and needs no elaboration here.
The ideal insecticide is one that adversely affects only the target species, sublimates without residue when desired, and has no negative environmental effects. As usual, the ideal is a potentially unattainable goal which, nonetheless, is worth striving for.
The desiratum of the present invention was to locate and identify a substance or substances naturally occurring in some part of the environment, which has positive effects, or is at least neutral, upon all fauna and flora other than the targeted pests and is especially lethal upon those pests. Such a substance must also be free of metabolites or breakdown components which themselves are toxic or cause environmental harm. The search for such a substance has been ongoing. To date, however, this search has discovered no alternatives which are truly satisfactory.
One prior art effort to create a non-toxic insecticide used for controlling insect infestation is based on using a non-toxic carrier such as diatomaceous earth which is thoroughly laced with a bait substance such as cane molasses, cane sugar, dextrin, and the like and which after ingestion mechanically kills the insects by lacerating the body and causing the loss of vital fluids. However, such an insecticide poses a threat to non-targeted life and as such does not attain the aforestated desiratum.